Basic fibroblast growth factor (bFGF) receptors are upregulated on the proliferating cells that are present in various diseased states, including restenosis, various cancers and various opthamalogical conditions and syndromes. It has been shown that bFGF coupled to the toxin, saporin inhibits the growth of proliferating cells in both in vitro and in vivo models of these diseases. Using recombinant gene technology fusion proteins of bFGF-saporin (FGF-SAP) have been expressed in E. coli. At present, a sub-optimal protein purification protocol exits that results in milligram quantities of FGF-SAP from gram quantities of starting material.The specific aims of this research are to (1) develop an efficient and expedient protein purification protocol in order that gram quantities of FGF-SAP can be manufactured to facilitate preclinical and clinical trials, (2) ensure that this protocol will lend itself to easy scale up and conversion to a GMP process in the following phase of the work and (3) develop a number of bioanalytical assays to characterize the products which will be used in the validation documentation of the GMP process.